Magnetic door latch



Jan. 6, 1959 T P. FQLEY MAGNETIC DOOR LATCH Filed Oct. 5, 1955 FIG! FIG.2

I INVENTOR. T'HOMAS P- FOLEY BY% HIS ATTORNEY United State P tm MAGNETIC DOOR LATCH Application October 5, 1955, Serial No. 538,737 6 Claims. (Cl. 292251.5)

The present invention relates to magnetic latches for doors and is more particularly concerned with magnetic latches for refrigerator cabinets and the like including double-walled door structures and a compressible gasket surrounding the access opening to the cabinet.

Magnetic latches ordinarily comprise a magnet assembly mounted on either a door or cabinet member and an armature mounted on the other member for physical contact with the pole faces of the magnet assembly when the door is in a closed position relative to the cabinet member. In the case of certain cabinet structures, such as refrigerator cabinets provided with a compressible gasket for sealing the space between the door and the cabinet member, the closed position of the door may be defined as that in which the compressible gasket is partially compressed to an extent which effects the satisfactory sealing 'but not to such an extent that the gasket is permanently deformed. For that reason refrigerator door latches and the like should be adjustable in order that the latched door will be in the proper position to provide the required compressive forces on the gasket.

It is a primary object of the present invention to provide an improved magnetic door latch including adjustable pole pieces for regulating the door-latching'position.

Another object of the invention is to provide a magnetic latch including adjustable pole pieces and a simple and effective means for locking the pole pieces in the ad justed position.

A further object of the invention is to provide, in combination with a door structure including inner and outer spaced magnetic walls, a magnetic latch assembly including a novel mounting arrangement for supporting the latch assembly at least partially within the space between the inner and outer door walls.

Further objects and advantages of the invention will become apparent in the following description and the fea tures of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this application.

In accordance with the present invention, there is provided a magnetic latch for holding a door member in closed position relative to a cabinet member comprising a fixed armature on one of the members and a magnet assembly rigidly mounted on the other member. The magnet assembly includes a non-magnetic supporting member having an elongated recess therein. Disposed within the recess are an elongated magnet having arcuate grooves provided in the end thereof and a pair of cylindrical pole pieces engaging or nesting in the arcuate grooves and extending generally normal to the magnet axis. The pole pieces are loosely mounted in the supporting member by means of screws or bolts axially threaded into the base portion of the pole pieces whereby rotation 'of the pole pieces on the mounting or anchoring screws provides means for adjusting the position of the pole pieces relative to the magnet and the magnet-supporting member. A cover plate serves to retain the magnet within the recess in the supporting member and includes holes 2,867,467 Patented Jan. 6, 1959 or apertures for receiving the outwardly extending face portions of the pole pieces in such a manner that, when the cover plate is in place, the holes or apertures cooperate with the face portions of the magnet pole pieces to prevent rotation thereof. In the preferred form of the invention, the supporting member includes means for rigidly mounting the supporting member on the outer wall of a double-wall door structure with the supporting member at least partially disposed within the space between the door wall and means for removably securing the cover plate on the inner wall of the door thereby utilizing efficiently the space between the door walls.

For a better understanding of the invention reference may be had to the accompanying drawing in which Fig. 1 is a vertical sectional view of a portion of the refrigerator cabinet including an embodiment of the present invention; and

Fig. 2 is a view generally along line 2-2 of Fig. 1 with a portion of the latch housing broken away to show the internal structure of the latch.

' Referring to Fig. l of the drawing there is shown a vertical sectional view of a portion of a refrigerator comprising a cabinet Wall 1 and a door 2 for closing the access opening to the storage compartment within the refrigerator cabinet. A gasket 3 mounted on the door provides means for sealing the space between the door and the cabinet around the access opening to the cabinet. The door comprises an outer wall 4 and an inner wall 5 spaced from the outer wall with the space between the two walls filled with insluation 6. It is to be understood that the'door is pivotally mounted by means of hinges (not shown) along one vertical edge thereof and the portion of the cabinet illustrated in Fig. 1 comprises the opposite vertical edge portion of the refrigerator door and adjacent cabinet wall.

The magnetic latch in the present invention, which is designed to hold the door in a closed position relative to the cabinet, or more specifically to the face portion 7 surrounding the access opening to the cabinet storage compartment, comprises a magnet assembly generally indicated by the numeral 8 mounted on the door 2 and an armature or keeper 9 fixed to the cabinet. It is to be understood that when the cabinet face portion 7 is composed of magnetic material it may comprise the cooperating armature. However, if it is composed of a non-magnetic material or if its magnetic mass is not sufiicient, an armature member may be provided as shown.

The magnet assembly 8, which is rigidly mounted on the door 2, comprises a non-magnetic supporting member 11 partially disposed Within the space between the planes of the inner and outer door walls 4 and 5 and secured to the outer wall 4 by means of non-magnetic screws 12. In the face portion of the supporting member 11 is an elongated recess 13 which partially houses a permanent magnet 14. This magnet substantially fills the cross-sectional area of the recess 13 but is somewhat shorter than the recess to provide room at the opposite ends of the recess for a pair of pole pieces 15.

Each of the pole pieces 15 is of 'a cylindrical shape at that portion 1t? engaging the ends of the magnet 14 and arcuate or cylindrical grooves 19 are provided at each end of the magnet to provide good contact between the pole pieces and the magnet. As will be evident from Fig. 1, the pole pieces extend generally normal to the longitudinal axis of the magnet and include outwardly extending face portions 21 extending in a direction away from the magnet for contact with the armature 9.

As both the magnet assembly and armature portions of the latch are rigidly or solidly mounted on their respective supporting members, the point at which the face portion 21 of the pole pieces contacts the armature portion of the cabinet member determines the position of the door 2 relative to the face portion 7 of the cabinet. In this position, the gasket 3 should be compressed to i an extent suificient to seal the space between the door and cabinet around the access opening to the cabinet storage compartment. Therefore, in order to provide the desired gasket compression, it is desirable to provide means for adjusting the positions of the pole face sections 21 relative to the magnet 14, or more specifically to the inner wall of the door, to provide that spacing which effects the desired gasket compression.

The pole adjusting means provided by the present invention comprises a pair of anchoring bolts 23 which are loosely positioned in apertures 24 provided in the bottom portion 25 of the supporting member and which are threaded axially into the cylindrical end portion 1% of the pole pieces. By rotating the pole pieces relative to the bolts 23, the pole pieces will be caused to move in and out of the latch mechanism or assembly along a line perpendicular to the magnet axis thereby providing means for obtaining the proper spacing between the door 2 carrying the magnet assembly and the cabinet face portion 7 forming or carrying the armature. In order to prevent the bolts 23 from turning during rotation of the pole pieces, the bolts are provided with head portions of a non-circular, or more specifically a polygonal or square shape, and these bolt heads 28 are adapted to be received in cooperating depressions 29 provided in the bottom of the supporting member. It will be noted from Fig. 1, when the magnet assembly is mounted on the door, the bolts 23 are held in their proper position by the outer wall 4 of the door. Whenever the outer wall 4 of the door is composed of magnetic material, it is of course essential that these bolts be made of some suitable non-magnetic metal in order to prevent undue flux leakage through the Wall 4.

To retain the magnet 14 in the recess 13 and to prevent undesired rotation of the pole pieces once they have been adjusted, there is provided a removable non-magnetic cover plate 30 which overlies the recess 13 and is suitably secured to the inner Wall 5 of the door by means such as screws 31. The face sections 21 of the pole pieces extending outwardly from the supporting member 11 are received in cooperating holes 32 provided in the cover. plate 30. Preferably, the pole face sections 21 are of square cross-section as are also the holes 32 provided in the cover plate so that, when the cover plate is mounted in place on the inner wall 5 of the door, the cover plate, or more specifically the side walls of the holes 32, prevent accidental rotation and displacement of the pole pieces. While the face sections 21 and holes 32 have been shown as being of a square configuration, it is to be understood that any non-circular cooperating shapes can be employed for the purpose of locking the pole pieces against rotation when the cover plate is in place. In order to adjust the pole pieces, it is only necessary to remove the cover plate 30 and rotate the pole pieces.

Since most refrigerator doors, particularly the peripheral or edge portions thereof, are composed of steel or other magnetic material which would interfere with the proper action of the magnetic latch, the mounting arrangement employed in the practice of the present invention preferably includes the forming of a depression in the inner wall 5 of the door so that those portions of the inner wall generally indicated by the numerals 34 and 35 immediately adjacent the latch assembly will be disposed more closely adjacent the outer wall 4 of the door and hence more remote from the main flux path of the magnet assembly. In the arrangement shown in the drawing, there is also provided in the depressed portion of the inner door wall, a pair of spaced openings 38 adapted to receive rearwardly directed portions 39 of the supporting member and permit these portions to contact theouter wall 4 of the door for direct mounting thereon. Also by this arrangement, the heads 28 of the anchoring bolts 23 are brough close enough to the outer wall 4 of the door so that they will be held in their cooperating depressions 29 by this outer door wall.

While there has been shown and described a particular embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention, and it is intended by the appended claims to cover all such changes and modifications as come Within the true spirit and scope of the invention.

What I claim as new and desire to secureby Letters Patent of the United States is:

1. A magnetic latch for holding a door member in closed position relative to a cabinet member, said latch comprising a recessed supportingv member adapted to be mounted on one of said members, an elongated magnet disposed in said recess, a pair of cylindrical pole pieces in said recess in contact with mating arcuate grooves provided in the opposite ends of said magnet, said pole pieces including non-circular face portions extending outwardly from and normal to the axis of said magnet, means effective upon rotation of said pole pieces to adjust the positions of said face portions, and a removable non-magnetic cover plate overlying said recess and retaining the magnet therein, said cover plate including non-circular holes for receiving the face portions of said pole pieces and preventing rotation thereof.

2. A magnetic latch for holding a door member in closed position relative to a cabinet member, said latch comprising a recessed supporting member adapted to be mounted on one of said members, an elongated magnet disposed in said recess, a pair of cylindrical pole pieces in said recess in contact with mating arcuate grooves provided in the opposite ends of said magnet, said pole pieces including non-circular face portions extending outwardly from and normal to the axis of said magnet, means including apertures in the bottom Wall of said supporting member and anchoring screws extending through said apertures and threaded axially into said pole pieces effective upon rotation of said pole pieces to adjust the positions of said face portions, and a removable non-magnetic cover plate overlying said recess and retaining the magnet therein, said cover platev includingnon-circular holes for receiving the face'portions of said pole pieces and preventing rotation thereof.

3. A magnetic latch for holding a door member in closed position relative to a cabinet member, said latch comprising a recessed supporting member adapted to be mounted on one of said members, an elongated magnet disposed in said recess, a pair of cylindrical pole pieces in said recess in contact wtih mating arcuate grooves provided in the opposite ends of said magnet, said pole pieces including square face portions extending outwardly from and normal to the axis of said magnet, means effective upon rotation of said pole pieces to adjust the positions of said face portions, and a removable non-magnetic cover plate overlying said recess and retaining the magnet therein, said cover plate including square holes for receiving the face portions of said poles and preventing rotation thereof.

4. A magnetic latch for holding a door member in closed position relative to a cabinet member, said latch comprising a recessed supporting member adapted to be mounted on one of said members, an elongated magnet disposed in said recess, a pair of cylindrical pole pieces in said recess in contact with mating arcuate grooves provided in the opposite ends of said magnet, said pole pieces including square face portions extending outwardly from and normal to the axis of said magnet, means including apertures in the bottom Wall of said supporting member and anchoring screws extending through said apertures and threaded axially into said pole pieces eifective upon rotation of said pole pieces to adjust the positions of said face portions, and a removable non-magnetic cover plate overlying said recess and retaining the magnet therein, said cover plate including square holes for receiving the fact portions of said poles and preventing rotation thereof.

5. A magnetic latch for holding a door comprising spaced magnetic inner and outer walls in a closed position relative to a cabinet, said latch comprising a supporting member secured to said outer Wall, said member having an elongated recess therein, an elongated magnet disposed in said recess, said magnet being provided with areuate grooves at the opposite ends thereof, cylindrical pole pieces disposed in the end portions of said recess in engagement with the arcuate grooves at the opposite ends of said magnet with their axes extending normal to the axis of said magnet, said recess having apertures therein coaxial with said pole pieces, means for loosely and adjustably securing each of said pole pieces to said supporting member including one of said coaxial apertures in said supporting member, a screw loosely extending through said aperture and threaded axially into one end of one pole piece, means for preventing rotation of said screw relative to said supporting member, and a removable non-magnetic cover plate secured to said inner door wall and overlying said recess, said plate having holes therein for receiving the opposite ends of said pole pieces, said opposite ends of said pole pieces and said holes being of non-circular shape to prevent rotation of said pole pieces when said cover plate is in place.

6. A magnetic latch for holding a door comprising spaced magnetic inner and outer walls in a closed position relative to a cabinet, said latch comprising a supporting member secured to said outer wall, said meniber having an elongated recess therein, an elongated magnet disposed in said recess, said magnet being provided with areuate grooves at the opposite ends thereof, cylindrical pole pieces disposed in the end portions of said recess in engagement with the areuate grooves at the opposite ends of said magnet with their axes extending normal to the axis of said magnet, said recess having apertures therein coaxial with said pole pieces, means for loosely and adjustably securing each of said pole pieces to said supporting member including one of said coaxial apertures in said supporting member, a screw loosely extending through said one aperture and threaded axially into one end of one pole piece, said support having a depression in the bottom wall thereof, said depression and the head of said screw comprising wall portions adapted to prevent rotation of said screw, said screw head being retained in said depression by said outer door wall, and a removable non-magnetic cover plate secured to said inner door wall and overlying said recess, said cover plate having holes therein for receiving the opposite ends of said pole pieces, said opposite ends of said pole pieces and said holes being of non-circular shape to prevent rotation of said pole pices when said cover is in place.

References Cited in the file of this patent UNITED STATES PATENTS 

